Hemostasis Reference Laboratory

Activated Partial Thromboplastin Time (APTT)

• Transaction Code: 3200-05
• CPT Code (Suggested): 85730

The activated PTT is a kinetic screening test that measures the recalcification time of plasma after incubation. The APTT assesses the coagulation factors of the intrinsic pathway (factors XII, XI, IX, VIII, X, V, prothrombin, and fibrinogen).

The APTT will be prolonged in the presence of a factor deficiency, factor inhibitor, heparin or lupus-like inhibitors. Shortening of the APTT can occur as a result of coagulation factor activation due to a traumatic venipuncture, inadequately processed sample, or disseminated intravascular coagulation (DIC).

• Sample Required: 0.5 ml frozen plasma x4 or (2) 3.2% sodium citrated tubes, 5 ml each.
• See Sample Requirements when ordered with other tests.
• Normal Range: Contact laboratory
• Analytic Time: Within 5 working days